Billie Eilish Pirate Baird O'Connell was born in Los Angeles, California, to actress and teacher Maggie Baird and actor Patrick O'Connell. Her middle name, Eilish, was originally meant to be her first name, while Pirate was to have been her middle name. However, after her grandfather William Baird died while her mother was pregnant, her parents decided to name her Billie, after her grandfather.

Eilish started playing the ukulele at age six and joined the Los Angeles Children's Chorus at age eight. She also began taking dance classes and performed at talent shows. Her parents, both musicians, encouraged her and her older brother Finneas to explore various artistic interests, including music, dance, and acting.

At the age of 11, Eilish wrote her first 'real' song, inspired by the television series 'The Walking Dead'. This early start in songwriting was facilitated by her mother's songwriting class, which laid the groundwork for her future career.

Eilish recorded and released her debut single 'Ocean Eyes', which was originally composed by her brother Finneas for his band. The song found overnight success on SoundCloud and marked the beginning of her public music career.

Eilish released her debut extended play (EP) 'Don't Smile at Me', which included her earlier singles 'Ocean Eyes', 'Bellyache', and 'Bored'. The EP was commercially successful, reaching the top 15 of record charts in several countries, including the US, UK, Canada, and Australia.

Eilish's debut studio album 'When We All Fall Asleep, Where Do We Go?' debuted atop the US Billboard 200 and UK Albums Chart. The album was one of the year's best-selling albums and included the hit single 'Bad Guy', which became the first song by an artist born in the 21st century to top the US Billboard Hot 100.

At the 2020 Grammy Awards, Eilish received six nominations and won five awards, including Album of the Year for 'When We All Fall Asleep, Where Do We Go?'. This made her the youngest artist to win the Album of the Year award.

Eilish released her second studio album 'Happier Than Ever', which topped the charts in 25 countries. The album continued her streak of critical and commercial success.

Eilish performed the theme song 'No Time to Die' for the James Bond film of the same name, which topped the UK Singles Chart and won the Academy Award for Best Original Song in 2022.

Eilish wrote and performed 'What Was I Made For?' for the fantasy film 'Barbie', which became her second number-one single in the UK and earned her a second Academy Award.

Eilish released her third studio album 'Hit Me Hard and Soft', which was met with critical acclaim. The album spawned the US top-five singles 'Lunch' and 'Birds of a Feather', with the latter becoming her first number-one on the Billboard Global 200.